Laska, Simone ; Lottspeich, Friedrich ; Kletzin, Arnulf (2003)
Membrane-bound hydrogenase and sulfur reductase of the hyperthermophilic and acidophilic archaeon Acidianus ambivalens.
In: Microbiology (Reading, England), 149 (Pt 9)
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
A sulfur reductase (SR) and a hydrogenase were purified from solubilized membrane fractions of anaerobically grown cells of the sulfur-dependent archaeon Acidianus ambivalens and the corresponding genes were sequenced. The SR reduced elemental sulfur with hydrogen as electron donor [45 U (mg protein)(-1)] in the presence of hydrogenase and either 2,3-dimethylnaphthoquinone (DMN) or cytochrome c in the enzyme assay. The SR could not be separated from the hydrogenase during purification without loss of activity, whereas the hydrogenase could be separated from the SR. The specific activity of the hydrogenase was 170 U (mg protein)(-1) with methyl viologen and 833 U (mg protein)(-1) with DMN as electron acceptors. Both holoenzymes showed molecular masses of 250 kDa. In SDS gels of active fractions, protein bands with apparent masses of 110 (SreA), 66 (HynL), 41 (HynS) and 29 kDa were present. Enriched hydrogenase fractions contained 14 micro mol Fe and 2 micromol Ni (g protein)(-1); in addition, 2.5 micromol Mo (g protein)(-1) was found in the membrane fraction. Two overlapping genomic cosmid clones were sequenced, encoding a five-gene SR cluster (sre) including the 110 kDa subunit gene (sreA), and a 12-gene hydrogenase cluster (hyn) including the large and small subunit genes and genes encoding proteins required for the maturation of NiFe hydrogenases. A phylogenetic analysis of the SR amino acid sequence revealed that the protein belonged to the DMSO reductase family of molybdoenzymes and that the family showed a novel clustering. A model of sulfur respiration in Acidianus developed from the biochemical results and the data of the amino acid sequence comparisons is discussed.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2003 |
| Autor(en): | Laska, Simone ; Lottspeich, Friedrich ; Kletzin, Arnulf |
| Art des Eintrags: | Bibliographie |
| Titel: | Membrane-bound hydrogenase and sulfur reductase of the hyperthermophilic and acidophilic archaeon Acidianus ambivalens. |
| Sprache: | Englisch |
| Publikationsjahr: | 2003 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Microbiology (Reading, England) |
| Jahrgang/Volume einer Zeitschrift: | 149 |
| (Heft-)Nummer: | Pt 9 |
| Kurzbeschreibung (Abstract): | A sulfur reductase (SR) and a hydrogenase were purified from solubilized membrane fractions of anaerobically grown cells of the sulfur-dependent archaeon Acidianus ambivalens and the corresponding genes were sequenced. The SR reduced elemental sulfur with hydrogen as electron donor [45 U (mg protein)(-1)] in the presence of hydrogenase and either 2,3-dimethylnaphthoquinone (DMN) or cytochrome c in the enzyme assay. The SR could not be separated from the hydrogenase during purification without loss of activity, whereas the hydrogenase could be separated from the SR. The specific activity of the hydrogenase was 170 U (mg protein)(-1) with methyl viologen and 833 U (mg protein)(-1) with DMN as electron acceptors. Both holoenzymes showed molecular masses of 250 kDa. In SDS gels of active fractions, protein bands with apparent masses of 110 (SreA), 66 (HynL), 41 (HynS) and 29 kDa were present. Enriched hydrogenase fractions contained 14 micro mol Fe and 2 micromol Ni (g protein)(-1); in addition, 2.5 micromol Mo (g protein)(-1) was found in the membrane fraction. Two overlapping genomic cosmid clones were sequenced, encoding a five-gene SR cluster (sre) including the 110 kDa subunit gene (sreA), and a 12-gene hydrogenase cluster (hyn) including the large and small subunit genes and genes encoding proteins required for the maturation of NiFe hydrogenases. A phylogenetic analysis of the SR amino acid sequence revealed that the protein belonged to the DMSO reductase family of molybdoenzymes and that the family showed a novel clustering. A model of sulfur respiration in Acidianus developed from the biochemical results and the data of the amino acid sequence comparisons is discussed. |
| Fachbereich(e)/-gebiet(e): | 10 Fachbereich Biologie > Sulfur Biochemistry and Microbial Bioenergetics ?? fb10_mikrobiologie ?? 10 Fachbereich Biologie |
| Hinterlegungsdatum: | 24 Mai 2011 08:49 |
| Letzte Änderung: | 05 Mär 2013 09:48 |
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